Rotating machine parts must sometimes be mounted in constricted space conditions. Consequently, assembly and dismantling facilities are greatly restricted. When designing such machine parts, an attempt is therefore made to limit the overall area as much as possible. One system that has previously been adopted is to separate the bearing unit of such machines in some way so that the individual elements can be installed consecutively.
Various methods of solving the above problem have been disclosed. For example, one method is to divide roller bearings axially into a top and bottom bearing half. These two bearing halves then have to be connected using relatively expensive clamping means. It has been proposed, for example, that the inner race of a roller bearing divided in the prescribed manner should be clamped on a shaft by means of clamp rings on both sides of the bearing surface. The outer race, which is also divided, is retained by means of a bearing housing. With this construction it is very important that the bearing joint should not lie in the load-carrying zone. The joint must also be very accurately machined.
A further improvement of the way in which rolling bearings can be installed is possible either by forming the rolling member running surfaces directly in one of the parts required to be mounted, or by forming the rolling bearing raceway in one of the two parts required to be mounted.
A disadvantage of forming the raceway directly on one of the parts for mounting is that the entire part for mounting must then be made from the relatively hard, high-grade material of a rolling bearing race if it is not to wear prematurely. The fitting of high-grade races in a softer, lower-grade basic material, on the other hand, has advantages. A solution of this kind is described in DE-OS 24 22 488, in which a double contact bearing is described for balls or superimposed rollers, consisting of raceways inserted in holders. The holders are made from a material different from the raceways. The race may be made from a single profiled bar and can be subjected to different heat treatments independently of the mounting. It is usually connected at the abutting ends by an oblique cut. This enables the resulting race to be opened up and contracted for assembly in the holder. This proposed solution, however, gives rise to various problems. First, care must be taken to ensure that the groove provided in the holder for the race corresponds exactly to the race width. Otherwise, the bearing may undergo axial shifting in excess of its tolerances ultimately resulting in damage to the bearing. Furthermore, a mounting of this kind is not secured against peripheral shifting in its seat. Thus the bearing tolerances can continually shift and again lead to bearing breakdown after a relatively short time. A second problem lies in connecting the two ends of the bearing sections. According to the method shown in the above-mentioned specification, as a result of the elasticity of the bearing material, a relatively large gap is inevitably left. Thus another place is created where bearing damage may occur. Finally, the mounting described does not save any space. This is true not only because the installation is conventional but also because the bearing itself occupies more space than a conventional bearing. At most, this method is suitable only for large-volume bearings where it is desired to save on valuable high-grade material.